Odd noise from the left rear

Jimny has made an odd noise twice today, both times we were going down hill in gear but off the throttle.
The noise was like very loud buzzing which was relative to road speed.
This morning it was a split second, and then this evening it was longer, and waa then followed by a clunk after which the buzzing had stopped.
Nothing to see at all, does anyone have experience of anything similar or have an suggestions as to what might be the problem?

What sort of tyres have you got and were you heavily loaded? Just wondering if it might have been a bit of trimming or debris catching on a tyre and being ripped off or if you have remoulded tyres could have been a bit of tread block giving up. If it drives ok and there is nothing obviously wrong after a thorough inspection I would be tempted to live with it and see if and when it does it again. If it had lost drive then that would be much worse and internal and expensive but it is probably just something caught on the tyres. probably.

The tyres are Yoko Geolandars and I had a look a look over them this morning, nothing's apparently wrong.
The only thing close to the tyre is the handbrake cable, but that's well tethered.

The Jimny was empty except for me and the road was clean.

It drives fine so as you say, live with it and investigate as and when it happens again.

Not sure if it's linked but I fitted a new mid rear exhaust last weekend, otherwise everythings standard.

Cheers.

Maybe after playing with exhaust .....

The clunk is exhaust section/hanger related

The buzzing is one of the heat shields, I junked the one on the cat ages ago as it buzzed.

I haven't had a look to see if the exhaust has moved, shall do that over the weekend.

The cat heat shield was already rattling so I've managed to stop that, it was getting more than a little irritating!
Then my other car started with the same rattle, fixed that and now the exhaust needs replacing on that....
Some weeks it feels like car maintenance never ends.

Cheers.